OFDM and OFDMA wireless communication systems under IEEE 802.16 use a network of base stations to communicate with wireless devices (i.e., mobile stations) registered for services in the systems based on the orthogonality of frequencies of multiple subcarriers and can be implemented to achieve a number of technical advantages for wideband wireless communications, such as resistance to multipath fading and interference. Each base station emits and receives radio frequency (RF) signals that convey data to and from the mobile stations.
A mobile station may include an RF front end with suitable circuitry for receiving the transmitted signals from a base station and processing the received signals in preparation for demodulation and decoding. The signal processing may include automatic gain control (AGC) and DC calibration. Proper AGC and DC calibration are important in order to increase the signal-to-interference-plus-noise ratio (SINR) without saturating the RF front end, thereby possibly leading to invalid data.